What is mean by effective depth how its works in reinfocement (civil engineering)

Question

how effective depth play reinforcement

Answer 1

In an R.C. beam cross section; the effective depth is the height from the begining of the R.C. section in compression to the c.g. of the reinforcing steel bars in tension. The design depth for any R.C. beam is the effective depth then a suitable concrete cover should be assumed.

Answer 2

I believe you are talking about reinforcing in a concrete member. The effective depth is the distance of the reinforcing steel from the compression side of the beam. Because concrete is in tension, the steel is there to resist the tensile forces, but because the steel is not located at the bottom edge of the concrete the effective depth is used in determining the various physical properties, i.e. bending resistance.